Waterslides are popular ride attractions for water parks, theme parks, family entertainment centers and destination resorts. The popularity of waterslide rides has increased dramatically over the years, and park patrons continue to seek out more and more exciting and stimulating ride experiences. Thus, there is an ever present demand for different and more exciting waterslide designs that offer riders a unique ride experience and that give park owners the ability to draw larger crowds to their parks.
Waterslides generally include an inclined water conveying course having an entry at an upper end and an exit pool or other safe landing structure at a lower end with a flow of water between the entry and the exit. A waterslide user slides down the course under the influence of gravity, with or without a conveyance means such as a flexible plastic mat, tube or raft. The water provides cooling fun for the ride participants, and also acts as a lubricant so as to increase the speed of the rider down the flume. Generally, the slide course is arranged along a sinuous or serpentine path with a series of bends, twists and turns which enhance the amusement value of the waterslide.
Typically a waterslide is formed from a plurality of straight and curved (“macaroni-shaped”) concave flume segments, connected together in an end to end relationship to define the inclined waterslide course. The flume segments can be closed tubes or open channels. The waterslide can comprise a mixture of different types of flume segments. For example, FIG. 1 of U.S. Patent Application Publication No. US2005/0282643 shows a waterslide comprising closed tube and open channel flume segments.
Often waterslide flume segments are fabricated from plastic or fiberglass resin composites and furnished with flanges via which they are bolted or otherwise fastened together. Most commonly the flume segments each consist of a constant cross-section and are either straight or swept along a straight or curved two- or three-dimensional space curve. In many cases the flume cross-section is circular. The linked cross-sections are typically congruent at their ends, thereby creating a composite path having, at all points, tangent vectors substantially normal to the cross-section of the flume or flume segments. Therefore it can be said that a typical waterslide flume consists of a generally constant cross-section swept across a continuous and smooth path.
It is not uncommon to connect flume segments having different cross-sections in a single waterslide. This is accomplished by use of a component known as a transition. A conventional transition is a generally straight segment of flume having at one end a cross-section identical to that of a first flume segment, and at the other end a cross-section identical to that of a second flume segment, with the first and second flume segments having a substantially constant cross-section along their length. The transition may be used to couple first and second straight flume segments or first and second curved flume segments, or a straight segment to a curved segment.
FIGS. 1 and 2 depict portions of prior art waterslides incorporating known transitions between flume segments having different cross-sections. For instance, FIG. 1 depicts a portion of a waterslide 100 having a transition 130 that connects a first upstream curved flume segment 110 having a first cross-sectional size and shape to a second downstream curved flume segment 120 having a larger and different cross-sectional size and shape. The transition 130 is a straight flume segment piece with a cross-section that changes along its length. Each cross-section of transition 130 is generally disposed perpendicular to a path which joins, in a continuous and smooth fashion, the slide path of first flume segment 110 and second flume segment 120. In this manner, the transition 130 provides a continuous, smooth composite slide path between the curved flume segments 110 and 120. Thus, cross-sections taken of the transition 130 (perpendicular to the slide path) between end flanges 140 and 150 (which are typically used to attach the transition 130 to the first and second flume segments 110 and 120, respectively) comprise generally smoothly modifying blends of the cross-sections of first flume segment 110 and second flume segment 120, thereby providing a safe and smooth ride path for the rider.
FIG. 2 depicts a plan view of a portion of a waterslide 200 with a transition 230 linking first and second straight flume segments 210 and 220, wherein the first, upstream flume segment 210 has a narrower cross-section than the second, downstream flume segment 220. The transition 230 is similar to the transition 130 used to link the curved flume segments in FIG. 1 in that the transition 230 is a straight flume segment with a cross-section that changes gradually along its length. Each cross-section of transition 230 is generally disposed perpendicular to the approximate linear ride path and direction of movement of the rider (shown as arrow 260) defined by the straight flume segments 210 and 220. As such, the transition 230 provides a continuous, smooth composite slide path between the straight flume segments. As shown in FIG. 2, the transition 230 may be generally curved as it extends outwardly from the first flume segments 210 to the second flume segment 220, or it may instead define a substantially straight outwardly-extending section that extends from the narrower flume segments 210 to the wider flume segment 220. In commonly used transitions, a curve joining the outward normals of the end faces of a transition is generally straight when viewed in plan.
Waterslides are distinct from many other amusement rides in that the actual path of a rider contains additional degrees of freedom beyond strict adherence to a path largely parallel to the slide path of the flumes in the waterslide. The rider (optionally on a raft or other conveyance device) can slide from side-to-side within the flume, while having an average direction of travel in the direction of the slide path. In most designs this side-to-side motion is inevitable due to the shape of the flume and the plan view of the slide path. In order for a rider to follow the slide path precisely, the flume underneath the path of the rider would need to tilt such that the normal acceleration due to a curved path of a rider moving at any velocity is counteracted entirely by the angle of the supporting surface with respect to the direction of gravity. As the flume does not rotate, the rider must translate across-the cross-section until the previously mentioned force balance is achieved. Certain waterslide rides rely entirely on the excitement of climbing a flume wall and then sliding downwards and then in some cases up another flume wall and so on in this side-to-side manner.
It is common in waterslides to use side-to-side oscillation and the attendant rise up the wall of the flume to create a safe yet more exciting ride experience. Oscillation is typically created by turns in the slide path of a waterslide. This generally requires long stretches and large radius turns in the slide path, using a large surface area of slide surface. Conventionally, wider flumes are used to permit larger side-to-side motion with higher upward displacements.
FIG. 3 depicts a plan view of a portion of a prior art waterslide 300 in which a first straight flume segment 310 is linked to the second straight flume segment 320 of the same cross-section, by a turn 330. The turn 330 may be defined by a separate flume segment, or instead, it may be formed as a portion of either one of the straight flume segments. The approximate ride path and direction of movement of the rider is shown as arrow 360. As the rider moves into turn 330, a continuation of the rider's original path directs the rider up the interior wall of turn 330. As the rider is now up a slope on the turn 330, the rider is urged by gravity in a downward direction pointing into the center of the turn. As the rider travels downhill toward the center of the flume segment 320, the rider also continues to traverse the ride path and turns the corner.
Thus, the turn 330 and the flume segments 310 and 320, in addition to defining a generally curved path of travel, also define a downward path component due to the concave or tubular wall shape of the flume segments. This downward path component is transverse to the curved slide path, so when the rider has completed the turn, and has returned to straight flume 320, the rider continues to travel in a side-to-side manner. The side-to-side component of velocity remains as an overshoot, creating an oscillating ride path 360. Thus, as the rider travels around turn 330 centrifugal forces move the rider across flume 320, creating an oscillation which is sustained in the ride path 360 for some distance after turn 330.
In order to create sufficient linear speed prior to the turn to create this side-to-side oscillation, a rider must have accelerated sufficiently, for example, by moving downhill from a certain height, thus creating a need for tall waterslide structures. In many waterslides the rider does not move side-to-side very much in the first few turning flume sections. Often, a straight section prior to a turn features an increase in grade and subsequent decrease in grade, creating a dropping section, to increase speed, thereby shortening the required straight.